Paper calendering apparatus



m sw y Feb 20, 940, GARDNER I PAPER GALENDERING APPARATUS Filed July 23, 1957 Patented Feb. 20,1940

PAPER omnpimnio mmrus Delbert G. Gardner, East Miiiinooket, Maine, assignor to Great Northern Paper Company, Millinocket, Maine, a corporation of Maine Application July as, 1931, Serial No. 155,234;

"2 Claims. (01. 92-70 This invention relates to paper making and particularly to threading the paper that comes from the drier of a paper making machine into and through the calenders.

Heretofore it has been customary to cause the paper to pass through the calender-s by the use of air blasts and scraper blades or doctors,

as described, for instance, in the Pope Patent No. 1,326,615, dated December 30, 1919.

The use of doctors, however, is objectionable in some instances and it is an object or the present invention to provide an arrangement of air blasts alone for detaching the leading edge of the paper from an upper roll of the calender stack and for forcing it against the surface 0! the next lowermost roll, thereby to guide the paper through the stack.

A further object of the invention is the provision of air blast means. for threading the paper through the calender stack, the air blast means providing an air jet or a series of jets which act on an upper calender roll approximately tangentially to the surface thereof and in a direction contrary to the direction 01' rotation of the roll to detach the leading end 01 thepaper from said upper roll and to move the end downwardlytoward the next lower roll, the air power of the jet acting approximately radially to the surface of the next lower roll so as to press the leading end of the paper sheet upon said lower roll and thereby to cause the paper to be adhereat to said lower roll so that it will move downwardly and through the stack.

A further object is generally to improve upon means for removing a paper sheet from one roll and transferring it to an adjacent roll.

Fig. 1 is a diagrammatically illustrated elevation of the calender stack and the end drying rolls of a paper making machine with which the present invention is associated.

Fig. 2 is an end elevation of the calender stack of Fig. 1.

Fig. 3 is an enlarged detail illustrating the relation between the air jets and the associated rolls of the calender stack.

Fig. 4 is a longitudinal view oi a section of air blast pipe having air blast orifices arranged in accordance with the present invention.

Fig. 5 is an enlarged section taken along line 5-5 of Fig. 4 and illustrating one of the air blast orifices.

Fig. 6 is a detail plan view of the air blast pipe and illustrating a set of orifices.

As herein illustrated the paper sheet l0, which at the time of threading through the paper making machine, may be a relatively narrow lead strip, passes irom the end drying rolls l2 upwardly to a calender stack l4 and into the nip between the uppermost roll I6 and the next lower roll l8 and around said roll and successively to the lower rolls 20, 22, 24, 26 and 28 to the larger diameter lowermost roll 30 from which the strip passes to a winding reel or other paper take-up not herein illustrated. v

The stack of calender rolls is supported in the usual manner between vertical frames 32 or the paper making machine and 'are free to rise and fall to maintain a nip on the paper sheet. The

paper sheet is passed from the last drying cyl- 22, 1921. In this construction and as herein illustrated, the paper sheet passes under an idler roll 34 and thence upwardly between upper and lower guide plates 36 and 38 which terminate close to and in line with the nip between the upper calender rolls l6 and l8. 7

A scraper or doctor 40 arranged in contact with the last drier cylinder l2 serves to detach the paper sheet from said roll and an air blast nozzle 42 serves to blow the paper sheet upwardly under the idler roll 34 and between the guide plates 36 and 38 into the nip of the upper calender rolls l6 and l8.

In accordance with the present invention an improved form of air blast means is provided to detach a leading end of the paper sheet from the discharge sides of upper calender rolls andto move the paper into contact with the surfaces of the cooperating lower rolls whereby to cause the paper to thread through the calender stack.

In accordance with the present invention a plurality of horizontal air blast pipes 44 are 10- cated behind each of the rolls I6, 20, 24 and 28 and approximately in the horizontal plane of the axis thereof and a similar series of horizontal air blast pipes 46 are arranged in front of and in approximately the horizontal plane of the rolls [8, 22 and 26 of the calender stack. The similar ends of said pipes 44 and 46 are connected by a supply pipe 48 to a supply line 50 through a quick opening valve 52 which, when opened, admits air to all of the air blast pipes. V

The air blast pipes 44 and 46 are or can be identical. Each pipe is provided with a plurality of longitudinally spaced groups of small, closely spaced orifices 56, each group as herein shown, consisting of three orifices, the spacing between the groups being any suitable amount as, for instance, 8 'or 9 inches, The orifices are relatively small in diameter as, for instance, f; inch spaced apart inch between centers. The spacing between the groups is sufilciently close to cause the full width of the paper sheetto be threaded through the calender stack'in the intended manner. The axes of the orifices 56 are preferably parallel and the orifices are so located in the under sides of the pipes 44 and 48 that they are approximately in the horizontal plane passing through the axis of the associated calender roll the axes of the orifices are directed in a line that is approximately tangential to the associated calender roll and approximately radial to the next lower roll, asis illustrated by the line 58, Fig. 3. r r

The spacing of the air blast pipes with respect to their associated calender rolls and the arrangement and disposition of the orifices 56 and the pressure of air supplied to the orifices is such thatjets or blasts of air issue from the orifices having boundaries approximately as illustrated by the lines 60 and 62, Fig. 3. That is to say the air jet from the group of orifices is conical and impinges against the rising surface of the associated roll as the roll I6, Fig. 3, over a con- .of the lower roll I8 over a considerable arc thereof and hence force the detached leading end of the paper sheet downwardly and press it upon the surface of the lower roll, thereby to cause the paper sheet to adhere thereto and to pass into the nip between the lower roll l8 and the next lower roll 20. It is found that the paper sheet when pressed firmly against the descending surface of a roll, as the roll l8, will adhere to said surface either by reasons of static electricity or because of the close contact between the paper sheet and the roll so that the leading endbf the paper is surely threaded through the stack of rolls. The action of the air blasts .on the successive rolls is the same as has been described. The edge of the paper can be detached from the 'lowerrnost roll in any suitable manner as by the use of a doctor 64 and guided to the winding reel or other paper take-up not shown.

, The use of sets of small orifices 56, made easily by drilling, provides sharply defined high velocity air blasts having a considerable dimension lengthwise of the calender rolls to act upon about the entire width of the usual lead strip.

I claim: I

1. .In a paper making machine, the combination of a pair of calender rolls, and means to detach the paper sheet from the surface of the upper roll and to carry the sheet -onto the surface of the next lower roll, said means comprising a pipe arranged parallel to the axis of the upper roll having an orifice located in approximately the horizontal plane passing through said axis to apply an air blast directed downwardly in a straight line to impinge against the surface of and approximately tangential to the upper roll counter to the direction of movement of the surface thereof and to impinge against the surface of and approximately radial to the lower roll with for each calender roll, each pipe having a series of groups of air openings arranged in approximately the same horizontal plane as the axis of the associated roll and parallel to the rollaxis,

and bored to direct air downwardly crosswise of the space between the cooperating rolls and not directed into the nip thereof in a stream broadening out from its outlet'point, the center line-of said stream being directed approximately tan gential to the calender roll served by said pipe and the lower portion approximately radial to the next lower calender roll.

DELBERT Gamma 

